The present invention relates to a magnetic reproduction apparatus provided with a crosstalk reduction system for performing a magnetic reproducing operation with use of at least two magnetic heads.
In conventional magnetic reproduction apparatus, such as embodied in the form of a VTR or a DAT reproduction apparatus, a magnetic head scans a target recording track and also part of tracks adjacent thereto at the same time. This for the reason that, generally, the scanning width of the magnetic head is larger than the recording track. When the width of the magnetic head is set large in this way, the scanning of the target track can be attained even when the scanning position of the magnetic head is shifted to any one of the pair of the adjacent tracks.
FIG. 4 explains the scanning condition of a prior art ordinary magnetic head. As illustrated, a magnetic head 1 having a plus azimuth angle scans a track Ta recorded on a magnetic tape T with a plus azimuth angle. During the scanning operation, the magnetic head 1 also scans part of tracks Tb1 and Tb2 having minus azimuth angles and adjacent to the track Ta.
When the magnetic head 1 scans the tracks Tb1 and Tb2 having different azimuth angles, the magnetic head also reproduces, in addition to a main signal based on the track Ta, a subsignal (crosstalk component) based on the tracks Tb1 and Tb2. The crosstalk component, which is a noise component of the main signal, acts to reduce the S/N ratio of the main signal. An example of circuits for improving the S/N ratio is a crosstalk reduction circuit.
As an example of such conventional ordinary crosstalk reduction circuits, there is proposed a circuit which extracts crosstalk components from latest (based on the latest scanning track) and past reproduction signals, inverts one of polarities of this two types of crosstalk components for addition thereof to thereby realize reduction (cancellation) of the crosstalk components. In this connection, the past reproduction signal refers to a signal which corresponds to a past scanned track different from the latest scanning track.
Scanning different tracks, in general, produces different contents (waveforms) of their crosstalk components. That is, as mentioned above, even when the addition of two types of crosstalk components of different tracks, it has been difficult to sufficiently reduce (cancel) the crosstalk components. In other words, it has been impossible to realize sufficient improvement in the S/N ratio of a reproduction signal.